Automatic calendar



Oct. 21, 1941. B. s. BALINSKI 2,259,603

AUTOMATIC 'CALENDAR Filed April 18, 1959' Sheets-Sheet 1 SA a 1 JAN 3 aFRI NOW

Oct. 21, 1941.

B. s. BALINSKI AUTOMATIC CALENDAR Filed April 18, 1959 4 Sheets-Sheet 2a gg.

Oct. 21; 1941- B. s. B ALINSKI AUTOMATIC CALENDAR Filed April 18} 1939 4Sheets-Sheet 3 Oct. 21, 1941. B. s. BALINSKI 2,259,603

AUTOMATIC CALENDAR Filed April 18, 1939 4 Sheets-Sheet 4 Patented Oct.21, 1941 UNITED STATESPATENT OFFICE AUTOMATIQ- CALENDAR Benjamin s.Balinski, Chicago, 111.

Application April 18, 1939, Serial No. 268,632

9 Claims. (01. 40-112) My invention relates to mechanical calen- 1 dars,and more particularly to those intended to operate over long periods,and my main object is to provide a calendar of this kind which performsits functions over a lifetime without attention or resetting as long asmotive energy is supplied to it. I

A further object of the invention is to include in the novel calendarmeans to automatically adjust the readings for the dates of the shorterand longer months, as well as those affected by leap years.

Another object of the invention is to group the date carriers in acompact series in order to have the calender take up as little roomaspossible consistent with a sufficient display of the readmgs.

An additional object of the invention is to provide a mechanism for thenovel calendar which is mainly grouped at one end thereof and verycompactly.

Another object of the invention is to render the calendar mechanismsuitable for actuation by an ordinary time piece, such as a springwoundor electric clock.

Animportant object of the invention isto provide a mechanism which islargely positivein action, contains few springs, and requires onlyoccasional lubrication to keep in proper condition.

With the above objects in view, and any others which may suggestthemselves from the descriptionto follow, a better understanding of theinvention may be had by reference to the accompanying drawings, inwhich-- i Fig. 1 is an encased 'view of the calendar combined with anumerical clock;

Fig. 2 is a full-sized front elevation of the calendar and itsmechanism;

Fig. 3 is a rear elevation;

Fig. 4 is a vertical longitudinal section through an axial plane;

Figs. 5 to are, respectively, sections taken onthe lines 5-5 to Ill-100iFig. 2;

Fig. 11 is a fragmental repetition of the upper portion of Fig. 8,partly broken away;

Fig. 12. is a fragmental elevation of a date carrier in the normalposition;

Fig. 13 is .a similar View, showing a changing position of said.carrier; 7

Fig. 14- is a mechanical detail showing a date control;

Fig. 15 is a mechanical detail showing a control for regular and leapyear months;

Fig. 16 is another view showing the controls for months and datechanges;

Fig. 17 is another detail showing the positions of certain controls forordinary,shorter and leap year months;

Fig. 18 is a typical drive mechanism for the calendar; and

Fig. 19 is an elevation of a disk-type dial front for the calendar.

Primarily, the novel calendar is intended to be read horizontally. Thus,the day reading is first at the left, then the date reading, then themonth, and finally the year. The readings are slightly above the centerof the calendar mechanism, and the front 20- of the calendar casing 2|is formed with rectangular openings 22 to disclose a given date. Thus,the corresponding legends in Fig. 2 are alined to show this date. Sinceit is preferable to, havethe calendar actuated by I a clock, aspreviously mentioned, the casing may combine the numerical clock 23above the cal I sired.

endar zone, as shown in Fig. 1.

The legends lofthe calendar are carried by a seriesof drums centeredsuccessively ona fixed 1 shaft25 andcarrying the legends on peripheraldialjp'ortion.

Thus, the day drum is indicated at 25,;the datedrum at 30, the monthdrum at 4|], the multiple-year drum at and the singleyear drum at 50.Fig. 4 shows the manner in which these drums are arranged on the shaft Acollar 25a on the latter retains the assembly against sliding motion; Asa modification Fig. 1.9 shows a series of disks arranged as the drums,where a fiat type of indicator is de- ,As seen in Fig. 4, the drum isformed with a hub 5| which is freely mounted on the shaft 25 andterminates at its left-hand end with a disk 52. The drum 45 also has avery short hub 45a: and a disk 4'! projected therefrom, the disks 41 and52 being separated by aspacing collar 48.

The drum 40 is also formed with a hub 4| which is reduced as a long tube42 to render the drum freely mounted on the shaft 25. The lefthandextremity of the tube 42 carries a large ratchet disk 43. a i I The,drum 30. is formed with a hub 3| which is reduced to form a tube 42,which is freely mounted on the tube 42 and carries a ratchet disk 33near its left-hand end, such end being extendedwith a radial arm 34.-The hubs 3| and 4| are spaced by a long collar 34a.

The tube32 receives a freely mounted tube 55 which carries a sector gear51 near its left-hand end, from which projects a radial arm 58 rigidlyconnected to the gear 51 by a pin 59.

The drum 26 is formed with a tubular hub 2! which freely encircles thetube 56 and carries a relatively small ratchet disk 28 at its left-handend.

It is understood that the drums turn periodically to display thesuccessive readings thereon, and the character of the mechanism requiresthat some turn in opposite directions from the others. According to themarkings in Fig. 2, it is evident that the day drum 2B and date drum 3!?move downwardly while the month-drum 43 and the 1 carrier to swing asideas the one for the even date year drums 45 and 50 move upwardly,arrowsindicating these movements in a rotary direction in other views.date drums 25 and 3B are instituted by the .for ward swing of the arm 58to the extent where its companion sector gear 51 strikes a stop lugfiflcarried by a cross rod 6| mounted in the lower part of the case 2|; andthe movement of the month and year drums 40, 45 and 53 is induced by thereturn swing of the said arm 58. This arm may thus be termed as thedriver for the calendar mechanism, and its companion gear is providedfor receiving energy from the, clock or other external source previouslymentioned, a suitable auxiliary gearing for this purpose being Themovements of the day and described in a later section. The design of thecalendar mechanism requires that the arm should have and accomplish asuflicient stroke for fully attaining the functions during, each of itsmovements, and it is therefore understood that the actuating unit willbe required to impart the full or sufficient stroke to the arm in eachdirection. The return of the arm 58 is induced by a spring 58a leadingto a'fixed rod 64.

As indicated in Figs. 2 and '7, the drum 26 is spider-like with theperipherallegend-bearing portions 29 extended side-wise like wings.order that these may come to the front indaily succession, the arm 58 ispreferably actuated in a forward direction at or shortly after midnight.The disk 28 carried by the drum has the ratchet formation indicated at29a in Fig. '7 and is formed with seven teeth. As noted in the samefigure, the sector gear 51 has pivoted to it at 511; a pawl 511) whichis urged against the periphery of the impelled at the same time as theday disk 28 to change the date reading on the drum 3!].

With the date drum 3!] about the same diameter as the day drum 26 inorder to lend the calendar assembly uniformity and compactness, it isevident that ther will not be sufficient room on the periphery of thedrum 30 to space the date carriers 39a in end-to-end succession. Itherefore overlap them, as shown in Figs. 8 and 11, and cause thecarrier for the previous date to move out of the way whereby to permitthe carrier of the even date to fully show in the zone of display. Thisis done by causing the previous descends into place. The means toaccomplish this is simple. Thus, the drum 30 is composite in its pliesas shown in Fig. 4 in order to accommodate pairs of spring blades 39b inrotary succession and extending radially a short distance beyond theperiphery of the drum. The date carriers are flat plates 39cwhich-according to Fig. 2are pivoted at their left-hand lower corners tothe drum by means of pins 39d. These pass through square blocks 39crigidly carried by the plates 390, the blocks occupying the placesbetween the extended portions of th spring blades 39?). Fig. 11 showsthe carrier of the previous date in a position to descend upon a stopbracket 39] shown in Figs. 2 and 8, and rigidly secured to the rod 3iThe carrier rests upon this bracket, but when the drum turns to lowerthe carrier, it is caused by the bracket to swing to the left, asindicated in Fig. 12, opposite corners of the block 39c then spreadingthe spring blades 39b. The further travel of the carrier causes it tosnap into position a quarter turn beyond its original place and remainfixed by virtue of the pressure of the spring blades as shown in Figs.13 and 2. Thus, the previous date reading is moved independently to aconcealed position on each movement of the drum 30, so as to leave theeven date reading in full view at the place of display. The next move ofthe drum causes the swung carrier to meet the upper end of a stopbracket 39g carried by the ratchet disk 28 by a spring 51d. Therefore,every forward stroke of the arm 58'that is, .in the direction of thearrow in Fig. '7-will be calculated to rotat the disk 28 a sufficientdistance to change the day reading in front. The disk 28 is of coursecontrolled by a check pawl 510 which is pivoted on a rod 62 located inthe rear of the casing. The spring 63 for the check pawl 510 is anchoredon another rod to the rear of the rod 62 and numbered 64. The dayreadings are thus advanced and repeated without incident.

It has been mentioned that the drum 30 is directly connected with aratchet disk 33, andthe latter is therefore intended to take a partialturn each day, in the manner of the day ratchet disk 28; to change thedate. The disk 33 is therefore formed with 3! peripheral teeth and isactuated by a large pawl 35. which is pivoted at its base on aside pin36 carried by the arm 58, and is drawn toward the periphery of the disk33 by aspring 31 secured between the pawl and the arm. These partsarejshown in Fig. 6, and it is noted that the disk 33 also has a checkpawl 38 underneath, the same being mounted on the rod 6| and with itsspring 39 anchored on a pin fila. It follows, therefore, that the disk33 would be Figs. 6 and 16.

rod 6|, so that the carrier is in this manner forced to swing back-inclock-wise directionto its original position on the drum, this position,however, being below the display zone and maintaining the carrier in theconcealed position.

It is recalled that the ratchet disk 43 is directly connected to themonth drum 4!]. The teeth of the disk 43 are of course twelve in number,to agree with the peripheral portions 46 of the drum, which carry thereadings. As was previously mentioned; the month drum is intended torotate in the opposite direction from the day and date drums, and itfollows, therefore, that the teeth 45a of the disk 43 are pointed in areverse direction, as shown in Fig. 5. In order that the disk 43 may bedrawn the distance of a tooth each month, a hook pawl 46 is also mountedon the side pin 36 of the arm 58 and is intended to fall in front of atooth 45a when the arm 58 has advanced the date disk 33 by means of thepawl 35 to a point where the reading is th first of the month. Theperipheral notch in the date disk 33 in this instance is deeper than theothers, as indicated at 33a in The pawl 35 has thus taken a deeper fall.The head of the hook pawl 46 carries a side pin 43a below a finger 35aforwardly projected from the pawl 35, as shown in Fig. 6. It follows,therefore, that the fall of the pawl posit the same in front of theproper tooth of anemone? thermonthadisk: 43; so; that ithereturnistroke.ofthe arm 58 draws' this'd-isk throughras partial turn: in @thedirection, indicated: by'the'rarrowinn Fi'g-.. 5 or 16-, raising thenext; month :reading; to the display: zone. Th8h00k: pawl 46 isnormally:5 urged away from the disk 43 by auspring 46z di-- rected' from the sidepin 36;- as'shown-in Figs. 6- and:16;- As noted in Fig. .5, the month''disk 43: receives a check pawl 46bunderneath, such: pawl being. pivoted'on therod-62: and urged. upwardly;-

by" a spring 460 which bears against-the'rod' 64: When the'hook pawl 45?draws. on the month disk- 43'-as: farback as thearm 58 is' calculated torecede; it might; be assumed that the spring; 462 'willJautom-atically,urgerthe hook: pawl to dis l5 en'gagethe disk at the end of the stroke.Yet; it" is possible that-this will not occur because-of: the; engaginghold of the pawl upon the dish-even: at-the endfofrthestroke: Ihavethereforeformed thechecktpaWl 46b forthe disk43 with a; round- 20 ed campoint 46d whosezinfluence as'it snaps= into-the" proper: tooth notch-ofthedisk isttoveryslightly urge the disk ahead, that is; slight= lybeyondthe point towhich it wastdrawn, This) action willautomatically-free-the-hook ofthe-: pawl :46; so that ithessamayieldsto. the'influence of the spring-462m swing. away; from theperiphery ofthe-disk43-..

It Will-be. recalled thatithe ratchet disk 52is carriedb ythe singleyear drumifl; and the disk is cut with asmanyteeth as therearerperipheral reading. divisions 50a. on the said rdrum; namely" ten,readingfrom '1' to .0. When the month; drum 40 has gone around once, itacts to shift theyear drum 50 a sufficient distance to display thernextfigure. Accordingly, the month drum carries a. pin 53- which is adaptedto meet a side'lug-54 when the. drum 40a rotates in the:directionindicated by theiarrow inrFig. 9. 'Ihe=lug54 is, carried. by a:bracket 55 pivoted'orr the.'rod;62 at its" lower end. To the upper: end:of the bracket' 55'ispivoted 'a lever 5510, this lever-extending belowthe pivot 51k to: be connected with its'lowerwend to'a stationary arm 65by--a draw-spring 66; The arms 55 is.fast on thB1I0d 62 and carriesalateral stop 45.,

pin filter-the bracket 55.- Theuppe-r'portion =01 the'leve-r55kcarriesea -crossmin 68; one ofwhose' sections-seatsin one-ofthe.-tooth notches 52a. of the ratchet disk 52'." Thus; as the side. pin53 of themonth. drum 'continuesttor impinge onthe- The 'movement justdescribed-serves to rotate the yeardrum 50+ one-revolution everytenyears, and this 'movement'is"employed. to act on the multipleyear drum45 to give! the same a partial turn to' secure the-even. ten-yearnumbers, such. as Ill; 20,- 30; etc. Accordingly, one toothnotch. 52b ofthe ratchet disk 52 is deeper'than-the other nine; as-shown in Fig; 9eOrdinarily, the motions of the-lever 557cand, cross-pin 68' do notaffect. the ratchet' disk 41, as; the latter is: of somewhat. smallerdiameter: thanthe disk:- 52; so. that the correspondingportion; ofthe-pin 58 simply" rides above the periphery-of thedisk4'1;

However; when! the 10-year change is: to be made;

the cross-pin 68 falls-into thedeep notch 52!) and at'the same time into:thetcompanion notch of" 70:

01- also :1 carried: by

year: 99,.'whi'ch2is over a: period solong; as tobe well :beyond the:average span of life.

It. is .evidentzxthat alcalendar of the type herein'adescribed mustprovide adjusting means for months-ewhichr have less than 31- days.Thus, April, June; Septemberand November have 30 days; leapt-yearvFebruary has 29 days and ordinary -February '28 days. This circumstance:affeats-the: date-drum; since the date must change to-the: 1st of" thenext month before the current monthisallowed'to run 31' days. presentvcalendar mechanism I cause thedatedrum'to be drawn through "twostepswhen the month ends with'.the-30th day, soithat the next date in: view'will. be' the" 1st of the following month. Likewise, I cause the drum tobe drawn throughithree' steps at the; end. of a:29-day month and:thrcugh four' steps at'the end of-a 28-day -fronta1point. The-pawl 35 issufficiently wide: to

travel overboth the date'disk 33 and the cam 10a, as appears in Fig. 3;Ordinarily, one tooth of the date: disk occurs-.infront of the cam fall10b, so that the advance-of the pawl 35 a short distancefarthersecuresthe partial turn of the disk throughtone date; It willnowbe apparentfrom Fig. 14 on l6xthat-if the sector plate 10 isswung ashort distance-in a clock-wise direction, another datewtooth will beexposed frontally of the cam fall 10b, so that-.onthe advancethe pawl 35will drop onto-the date dish a tooth earlier and so servejto push the'disk over the distance of two teeth before the pawl reachesthe endofits advance. It follows, then, that the backing of the cam 1|] stillfarther will accomplish-a longerdate:

mentioned is always present by the pull of a spring" upon the sectorplate toward a fixed bracket 12 carried by the side pin 6la, as seen inFig: 6. In this manner the sector plate is'drawn to a back limit" formedby a detent 13 which engages a notch I4 near the lower end of the cam10a, the detent'beinggpivoted on the rod 62; as indicated in Figs: 14'and 16;

With thesector cam Illa described as a control for the engaging functionof the pawl 35, it is necessary to determine how the various positionsof the cam arefixed by the exceptional month ,1 values previouslymentioned, that is, months having' 30, days, .29 days and 28 days. Thesevalues are-representedby-a set of angle cams 15 carried by the, month:disk 43 at points near its periphe-ry, as-clearly shown in- Fig; 5. Eachangle cam is pivoted-on a pin 16 carried by the disk; and

the tail 15a-of 'each'cam isurged bya wire spring. "in. clock-wisedirection to abut-a stop. pin 18, the spring extending from a pin 19 onthe disk. Considering the direction of rotation of the disk. 43, itis'seen" that each angle cam 15 and its tail 15arecede inclinedly fromthe pivot point".

The angle-cams 15 are five in number, four representing the 30-daymonths and the fifth the 29-day and;the.28'-day Februaries.- Behind the.10-year; drunr 45; the calendar is ,capable of displaying; readings;from"the':yeadr01 to the- In the the series of angle cams is a curvedarm 88 which is pivoted on'the rod 62 jointly with the detent 13, bymeans of a common hub 88a, indicated in Figs. 3, 5 and 14. Below thepivot 62 the arm 88 is drawn by a spring 8| to the cross-rod 64. Theupper portion of the arm 80 is deflected forwardly to form a finger 801)which is directly'in the path of each angle cam when the disk 43 takes arotary movement as shown in Fig. 5. Thus, a given angle cam changes fromthe position denoted by full lines in Fig.1? to either of the threepositions indicated by dotted lines in the same figure. The four anglecams at the lower right and upper left in Fig. 5 represent the -daymonths, and it may be assumed that these angle cams occur in theuppermost dotted line position in Fig. 17 as each in turn gets under thefinger 80b.

It was stated in an early section that'the tube 32 extended from thedate drum 30 carries a radial arm 34, and it maynow be specified thatthis arm is within the circle of the angle cams 15. The arm is taperedto a rounded point, as indicated at 3411, which travels close to thefree ends of the angle cam tails 15a as the date' drum pin 8! strikesthe inner side of the angle cam tail 15a. This means that the sector cam18a has moved over through the space of an extra tooth on the date disk33, permitting the pawl to engage the said disk one tooth earlier on theadvance and move the disk over through two dates. The arm 34 is sopositioned in relation to the array of dates on the drum 30 that thesetwo dates are the 30th and 31st. Consequently, for a 30-day month the30th and 31st date readings are moved over together when the firstreading of the next month is to be exposed.

The remaining angle cam 'I5at the top right in Fig. 5-is intended to setthe date drum for the 29-day and 28-day Februaries. The action inreference to this angle cam is precisely the same as in the previousinstances, except that this cam occurs in the middle dotted-lineposition of Fig. 17 when the 29-day month ends and in the bottom dottedline position when the 28- day month ends. These positions indicate thatthe tails of the respective angle cams are one and two steps fartherfrom the approachof the side pin 8| shown in Fig. 14, and that thesector plate 10 will swing correspondingly farther on its release by thedetent l3, offering increasing exposures of the periphery of the datedisk 33 for the progressively earlier engagement of the pawl 35. Itfollows, therefore, that the 29th, 30th and 31st date reading s'will bemoved over in unison at the end of a leap year February, and that the28th, 29th, 30th and 31st date readings will be similarly moved at theend of an ordinary February.

The February angle cam is not directly secured to the disk 43, but ispivoted on a pin 16a which passes through a slot 43a in the disk 43 andis carried by the outer portion of an arm 82 pivoted on the main shaft25 along the outer side of the disk 43, as indicated in Figs. 5 and 15.The disk 43 has an outwardly projecting fixed spindle 83 on which isjournaled an integralv assembly of a disk' cam 84 and a spur gear 85.The cam 84 is in the plane of the arm 82 and ordinarily presents acircular periphery to the latter as indicated in Fig. 5, the arm beingmaintained as a follower against the cam periphery by a spring 86 (seeFig. 5) directed to a pin 81 carried by the plate 43. The cam has a fiatperipheral portion 84a, and Fig. 15 shows the position of the arm 82when it is opposite such portion. In such event, the related angle cam15 is with its pivot in the upper part of the slot 43a; and when the cam84 is in the'position of Fig. 5, the angle cam is at the bottom of theslot. These positions correspond with the middle and lower dotted linepositions-of the angle cam in Fig. 17, the basic functions of thesehaving been previously described. I

The stationary shaft 25 carries a fixed spur pinion 88 in mesh with thegear 85. Considering that the month disk 43 undergoes one revolution ayear, a ratio of 4 to 1 between the gear 85 and the pinion 88 willimpart one revolution to the gear 85 every four years. The cam 84 is soarranged that its circular portion is opposite the arm 82 during threeordinary years and the fiat peripheral portion 84a is so located duringthe fourth or leap year. Consequently, during the leap year thecorresponding angle cam 15 will be at the height of the middle dottedillustration in Fig. 1'7 and change the end of the February reading onthe 29th, whereas during the other three years the angle cam will be inthe position of the lowermost dotted illustration in the same figure andchange the said reading on the 28th.

It will be noted that the cam fall 70b is as deep as the special notch33a of the date disk 33, the reason for this being to allow clearancefor the entry of the pawl 35' into the notch 33a. This is apparent inFig, 16, and it will be noted that to the left of the fall 1817 thesector plate 10 has a ledge 10c followed, by a stem 10d. The ledge is infront of the pawl 35 and even with the left-hand wall of the notch 33awhen the parts are positioned as in Fig. 16 for the change of the month.As for the stem 10d, it is ordinarily in spaced relation to the advancedposition of the pawl 35. Thus, when the dates of a 31- day month areconsecutively shifted, the pawl 35 rides'at the level of the regulartooth notches of the disk33. Now, when the pawl has advanced at a timewhere the detent 13 is withdrawn as previously described to release thesector plate 10 to the backing pull of the spring H, the stem 10d of thesector plate immediately moves to meet the front of the pawl 35, and theretraction of the latter checks the sector plate from a too rapid ornoisy return. On the advance of the pawl the deep notch 33a gives itaccess to the ledge 700 of the sector plate to re-set the pawl in theforemost position.

The auxiliary gearing for driving the sector gear 51 will now bedescribed. Fig. 18 shows an alarm or other special wheel 88a of theclock or other time device which turns one revolution at a given clocktime, which is of course every twelve hours. The wheel 88a carries aswiveled radius block 83 which is slidable in a slot 90 in one arm 9|of'a bell crank 92 which is pivoted at the angle on a stationary shaft93. A pawl 94 extends pivotally from the other arm of the bell crank tothe peripheries of a single-tooth ratchet gear sector 95 and amultiple-tooth ratchet disk 96, these units being journaled alongsideeach other on a stationary shaft 91. The gear sector ,p'awl movabledaily'relative to said .teeth to nor- 95, is operatively connectedthrough an intermediate pinion 98 to the sector gear 51. It isthe'function of the special wheel 88a to swing the bell crank 92 a givendistance in the counterclockwise direction and back with eachrevolution, this having the -efiectthrough the pawl 94-to turn the disk96 counter-clockwise the distance of one tooth, the disk remaining orbeing suitably held still on the return of the pawl. The tooth of thegear sector 95 receives the pawl at the same time when the sector gear51 is in the idle or rear position, so that this gear is advancedthrough its stroke by the action of the pawl 94. The time at which thespecial wheel. 88a induces the above movements is set to occur shortlyafter midnight, or at any time during the night, to procure thenecessary calendar advance for the next day. As a matter of example, theaction may occur at 12:01 a. m. Now, when the clock wheel 88a is againactuated at 12:01 p. m.its impulse to the calendar must not occur,asthat would advance the calendar againat noon. Alternating teeth of theratchet disk 96 therefore occur at a greater radius than the gear sectortooth, so that when the disk is again turned the pawl 94 will be higherand out of reach ofthe gear sector tooth. The above mechanism has beendescribed as a preferable one, although any other which serves theultimate purpose may-be employed. It is noted that the pawl 94 could outof the way or in a manner to be designed as a separate or auxiliaryunit. It is also possible to actuate the calendar mechanism from aremote source, that is, Where the clock or timer is elsewhere andtransmits its impulse electrically 'to a magnet or solenoid whosearmature is the actuator. It is feasible in this manner to control aplurality of calendars in different rooms,

'oflices or parts of a building from a centralized source, providing anautomatic calendar service.

It will be evident from the above description that a calendar isprovided which is fully automatic over the span of a lifetime. Withelectric current available in all communities in one form or another,the supply of the necessary energy is easily available for the mechanismwhich operates the calendar, whether the same is a clock incorporated inthe calendar housing or simply an electric timing device auxiliary tothe calendar mechanism. Considering its functions, the mechanism isquite simple and of a nature to be compactly designed so that it mayoccupy a minimum of room. Further, parts of the mechanism have a limitedoperation but once a day and other parts more seldom, so that wear ofthe mechanism is so slight as to be negligible. Further, it is a simplematter to approach the drums from the rear, to re-set them if necessary,by withdrawing the controls thereof momentarily. Finally, it will beobvious that the calendar can be built by modern manufacturing methodsto sell at a reasonable figure.

While I have described the novel calendar along specific lines, variousminor changes and refinements may be made therein without departing fromits principle, and I consider all such changes and refinements as comingwithin the scope and spirit of the appended claims.

I claim:

1. In an automatic calendar, a date unit having 31 teeth representativeof 31-day months, a

mally advance'xthe unit a step each day, a month unit; means actuated onthe last day-of-themonth 'by thedateunit to advance the month unit astep in the rotation of a calendar month,

and -a control governed by the positions of the month unitto acceleratethe date unit at the end I of months of less than 31 days a number ofsteps equal to the difference of days in such months, dates-of-the-monthand months-of-the-year 'dials carried by said date and month units anddisposing readingsin rotation in regionsof display, said pawl having anadvancing movement over several teeth, said control including a camalongside the teeth and of a height to normally withhold the pawl fromengaging the teeth until the final portion of its advance where the pawlmoves the date unit one tooth, means to retain the-cam in itsnormalposition, means to retract the cam when theretaining means isreleased,

elements carried by the month unit for the release of the retainingmeans at points corresponding to the display positions of months lessthan 31 days, and an-actuator-carried by the date unit and effective onsaid elements when the last daysof such-months are on display to releasethe retaining means and allow the cam to be retracted a distanceexposing to the pawl a number of saidteethequal to the difference ofdays in the shorter months from the -31 day months.

2. In an automatic calendar, a date unit having 31 teeth representativeof 31-day months, a pawl -movable-daily relative to said teeth tonormally teeth,'said control including a-cam alongside'the teethand of aheight'to normallywithhold the pawl from engaging the-teeth until thefinal portion of itsadvance where the pawl moves the date unit onetooth, means to'retain the cam in its normal position, means to retract.the cam when the retaining means is released, .elements carried=by themonth unit forthe release of the retaining means at points correspondingto the display positions of months less than 31 days, an actuatorcarried by the date unit, and a stop carried by the cam and effectivewhen meeting the releasing one of said elements to determine the extentto which the cam becomes retracted.

3. In an automatic calendar, a date unit having 31 teeth representativeof 31-day months, a pawl movable daily relative to said teeth tonormally advance the unit a step each day, a month unit, means actuatedon the last day-of-the-month by the date unit to advance the month unita step in the rotation of a calendar month, and a control governed bythe positions of the month unit to accelerate the date unit at the endof months of less than 31 days a number of steps equal to the differenceof days in such months, dates-of-the-month and months-of-the-year dialscarried by said date and month units and disposing readings in rotationin regions of display, said pawl having an advancing movement overseveral teeth, said control including a cam alongside the teeth and of aheight 'to normally withhold the pawl from engaging the teeth until thefinal portion of its advance where the pawl moves the date unit onetooth, means to retain than 31 days, an actuator carried by the dateunit, means carried bythe month unit independently positioning the oneof said elements relating to February dates, and a connection effectiveby the movement of the month unit to shift said element to vary thelast-day display of February dates from the regular 28th to theleap-year 29th.

4. In a calendar mechanism, a ratchet datedisk effective on rotation todisplay readings of dates of the month, a pawl reciprocable over thedisk periphery and effective on the advance to move the disk for dailydisplays to the end of the month, a companion-reverse-ratchet monthdiskeffective on step-by-step rotation to display readings of months, of,the year, the first-day tooth of the date-disk defining a deep notch, asecond pawl reciprocable over the month disk periphery and effective onretraction to move such disk in said rotation, and means between thepawls to lower the second one into engagement with the month-disk whenthe first pawl falls into said notch.

5. In a calendar mechanism, a date disk having 31 teeth representativeof 31-day months, a pawl adapted to be advanced daily relative to saidteeth to normally turn the disk a step each day, a month disk, meansactuated on the last day-ofthe-month by the date disk to advance themonth disk a step in the rotation of a calendar month, a cam alongsidethe periphery of the date disk and barring said pawl from engaging thedate disk before becoming efiective for said step, means influencing thecam to move in a direction opposite to the rotation of the date disk, adetent checking the movement of the cam in said direction, an extensionof the detent alongside the month disk, rockable units carried by thelatter at points corresponding to months shorter than 31 days and in thepath of said extension to be deflected thereby when intercepted, an armcarried by the date disk and, eifective to rock a deflected one of saidunits at a point consistent with the position of the pawl for thepremature engagement with the date disk to advance it through thenon-existent dates of the particular shorter months, the rocking of saiddeflected unit crowding the extension to disengage the detent from thecam and permit the same to move, and a projection carried by the cam tomeet said unit and stop the cam at a point to clear the pawl for saidpremature engagement.

6. The structure of claim 5, a false support for the February unitrelative to the month disk, and a second cam geared to the latter torotate once in four years, the support being influenced by said secondcam at the end of a leap-year February to move the related unit forwardand aifect said pawl accordingly.

7. The structure of claim 5, a follower arm pivoted co-axially with themonth disk, a stationary axle for the latter, a pinion fast on the axle,a planetary gear carried by the month disk in mesh with the pinion at a4 to 1 ratio, and a cam carried by the gear with a dwell to maintain therelated unit in a position to affect said pawl at the end of a regularFebruary and with a fall to move such unit forward at the end of aleap-year February and affect the pawl accordingly;

8. In a calendar mechanism, a date drum having peripheral sections forstep-by-step daily display, said sections overlapping in rotary sequenceto permit as many as 31 sections to be grouped compactly, and meansoperative when a given date section is on display to draw aside the nextoverlapping section, whereby to leave the displayed one in full view,the sections being pivoted at one of their corners to the drum, and saidmeans comprising an abutment in the motive path of the sections.

9. In a calendar mechanism, a date drum having peripheral sections forstep-by-step daily display, said sections overlapping in rotary sequenceto permit as many as 31 sections to be grouped compactly, and meansoperative when a given date section is on display to draw aside the nextoverlapping section, whereby to leave the displayed one in full view,and other means to replace the section drawn aside into the series at apoint beyond the zone of display, the sections being pivoted at one oftheir corners to the drum, and said other means being an abutment in themotive path of the moved section and efiective to swing it back tonormal position on the movement of the drum.

BENJAMIN S. BALINSKI.

